207 



WHEN INOCULATION IS NEEDED. 



To inoculate each leguminous crop every time it is planted re- 

 quires both labor and money, and it is a waste if inoculation is 

 not needed. On the other hand, if the crop is not inoculated, 

 and inoculation is needed, the farmer loses money. So it be- 

 comes of some importance to know what leguminous crops 

 should be inoculated. 



There is only one known way by which the farmer can learn 

 Avith certainty whether inoculation is needed, and that is to 

 grow the crop in the field. If the root-nodules do not develop 

 at all, or develop on only a few isolated plants, that leguminous 

 crop needs inoculation when planted in that field. If, however, 

 some nodules are present on almost every plant, inoculation is 

 probably not needed.. The simple experiment described on page 

 29 can be carried out by any farmer. By performing such an 

 experiment he can readily ascertain which of the leguminous 

 crops need inoculation when planted on his farm. To perform 

 such an experiment, however, takes time, and many farmers may 

 prefer to inoculate each leguminous crop rather than to take 

 time for experimenting. Although there is no other known way 

 of finding out with certainty as to the need for inoculation, there 

 is a certain amount of information that is helpful in deciding the 

 question. 



Leguminous crops such as clover, peas, beans, and others that 

 have been grown on farms in this State for many years, probably 

 need no inoculation. There are some persons, however, who 

 assert that it pays to inoculate every leguminous crop every time 

 it is planted. It may be true that such a common crop as red 

 clover may be improved by inoculation, even in New York State 

 where it has been grown extensively for many years. It has 

 never been proved conclusively one way or the other; but the 

 writer's opinion, based on casual observation, is that soils on 

 most farms in New York State are naturally well inoculated 

 with the bacteria that produce nodules on legumes that have 

 been repeatedly raised on the farms. On the other hand, alfalfa, 

 soy beans, cowpeas, and any other leguminous crop that has never 

 been raised on the farm, as a rule need to be inoculated when 

 planted for the first time. 



That inoculation is needed in most cases when alfalfa is grown 

 for the first time has been shown in Bulletin 313 of the New 

 York (Geneva) Agricultural Experiment Station. In one hun- 

 dred and three experimental fields of alfalfa, distributed in 

 thirty-nine counties of this State, only twenty-five were suc- 

 cessful without inoculation. The authors say that in beginning 

 to grow alfalfa proper inoculation of the soil is a point that 

 is worthy of the careful attention of any farmer in this State. 



